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N4377A Lightwave Detector

Data Sheets

E-to-O Amplitude and Phase Measurements Up           to 43.5 GHz or 70 GHz

The N4377A Lightwave Detector is a USB-powered, DC-coupled optical-electrical converter with built-in optical power meter capability. It enables frequency domain applications in photonics if used with a vector network analyzer or a spectrum analyzer.

S21 measurements, laser linewidth and modulation spectra

With amplitude and phase response correction data stored on board the device, vector network analyzers (such as PNA, PNA-X) can de-embed the converter from optical transmitter or modulator measurements, enabling accurate S21-parameter measurements in the photonic domain.

Electrical spectrum analyzers benefit from the converter’s low intrinsic noise and high bandwidth when performing laser linewidth and modulation spectrum measurements.

Calibration and re-calibration are independent from the electronic instrument the converter is used with.

Built-in optical power meter

A calibrated optical power meter provides average power measurements and enables insertion loss measurements, e.g. on optical modulators. A bar-graph display on the converter not only helps detect bent or broken fibers, bad connectors or missing signal, but also helps stay within the detector’s linear optical power range.

Single mode and multimode fiber versions

The N4377A Lightwave Detector is available for single mode fiber with 43.5 GHz and 70 GHz bandwidth with calibration wavelengths at 1310 nm and 1550 nm, as well as for multimode fiber with 43.5 GHz bandwidth and calibration at 850 nm.

The single mode fiber versions operate across and beyond the entire CWDM range, starting at 1260 nm and reaching to 1650 nm.

The 43.5 GHz version for multimode fiber offers calibrated measurements at 850 nm but can also be operated at SWDM wavelengths and wavelengths up to 1600 nm. An option adds calibration wavelengths at 1310 nm and 1550 nm.

N4364A Lightwave Transmitter Analyzer; a Lightwave Detector – network analyzer bundle

Combining the N4377A Lightwave Detector with a suitable network analyzer is made easy with the N4364A Lightwave Transmitter Analyzer bundle:

Start off by choosing a version of the N4377A Lightwave Detector that meets your wavelength and bandwidth requirements, then pick either a PNA-L, a PNA, a PNA-X or a USB-VNA from the list of available network analyzer options.

Finally, complete the configuration with a connectivity kit that matches the DUT’s RF connectors. These test kits consist of all required RF cables and an electronic calibration module. If needed, flexible test port cables and RF connector adapters are available as accessories.

Target Test Devices

Mach-Zehnder modulators (MZM), electro-absorption modulators (EAM), directly modulated lasers and transmitter optical subassemblies (TOSA) represent the most common optical components. They are typically tested for their frequency response over a range of operating currents and ambient temperatures. The N4377A’s built-in optical power meter allows to check the operating power, but also gives an indication of a bent fiber or a bad connection. Dual-drive optical modulators can be characterized with 4-port PNAs as illustrated in figure 2


Generally, all specifications are valid at the stated operating and measurement conditions and settings, with uninterrupted line voltage.

Specifications (guaranteed)

Describes warranted product performance that is valid under the specified conditions. Specifications include guard bands to account for the expected statistical performance distribution, measurement uncertainties changes in performance due to environmental changes and aging of components.

Typical values (characteristics)

Characteristics describe the product performance that is usually met but not guaranteed. Typical values are based on data from a representative set of instruments.

General characteristics

Give additional information for using the instrument. These are general descriptive terms that do not imply a level of performance.


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